Polyacrylate plastic compositions containing bis-aryloxy flame retardants

ABSTRACT

Z is bromine or chlorine, m and m&#39;&#39; are integers having a value of 1-7, y is an integer having a value of 1-5, i and i&#39;&#39; are integers having a value of 0-2, and A is cyano, nitro, lower alkoxy, lower alkyl, fluorine, dialkylamino, phenyl, halo-phenyl, benzyl or halo- benzyl, and alkylene is a straight or branched chain alkylene group having from one to six carbon atoms.   AND   WHEREIN ARYL IS FROM THE GROUP   Plastic compositions containing polyacrylates and bis-aryloxy compounds having the formula:

Ilnite States atet [191 Anderson *Mar. 4, 1975 POLYACRYLATE PLASTIC COMPOSITIONS CONTAINING BIS-ARYLOXY FLAME RETARDANTS [75] Inventor: Arnold L. Anderson, Alma, Mich.

[731 Assignee: Michigan Chemical Corporation, St.

Louis, Mich.

[ Notice: The portion of the term of this patent subsequent to Aug. 20, 1991, has been disclaimed.

[22] Filed: Feb. 8, 1973 [21] Appl. No.: 330,794

Related US. Application Data [63] Continuation-impart of Ser. No. 260,240, June 6,

1972, abandoned.

[52] US. Cl 260/45.9 R, 260/42, 260/42.22, 260/45.75 R, 260/45.95 G [51] Int. Cl. C08f 45/60 [58] Field of Search.... 260/45.9 R, 45.95 G, 613 B, 260/33.2 R, 2.5 AJ, DIG. 24; 106/15 FP [56] References Cited UNITED STATES PATENTS 3,385,819 5/1968 Gouinlock 260/45.75 R 3,560,441 2/1971 Schwarcy et a1 260/45.7 R 3,658,634 4/1972 Yanagi et al 161/403 3,717,609 2/1973 Kutner 260/45.95 G

Primary Examiner-M. J. Welsh Attorney, Agent, or Firm-Robert M. Phipps; James J. Mullen; Robert S. Frieman [57] ABSTRACT Plastic compositions containing polyacrylates and bisaryloxy compounds having the formula:

wherein aryl is from the group and 18 Claims, N0 Drawings ll POLYACRYLATE PLASTlC COMPOSITHONS CONTAINING EllS-ARYLOXY FLAME RETARDANTS This application is a continuation-in-part of copending application Ser. No. 260,240, filed June 6, 1972 and now abandoned. The entire specification of this case, Ser. No. 260,240, is to be considered as incorporated herein by reference.

The prior art considered in conjunction with the preparation of this application is as follows: US. Pat. Nos. 2,130,990; 2,186,367; 2,329,033; 3,666,692; 3,686,320; 3,658,634; German Pat. No. 1,139,636; German Pat. No. 2,054,522; Japanese Pat. No. (72) 14,500 as cited in Volume 77, Chemical Abstracts, column 153737k (1972); Chemical Abstracts, Volume 13, column 448 Chemical Abstracts, Volume 31, column 7045 and Journal of the Chemical Society, pages 2972-2976 (1963). All of these publications are to be considered as incorporated herein by reference.

The present invention relates to plastic compositions containing polyacrylates. More specifically, the present invention covers plastic compositions containing polyacrylates and certain bis-aryloxy compounds (hereinafter defined) as flame retardants for said plastic compositions.

Polyacrylates and utility thereof are known in the art as exemplified by Acrylic Resins, M. B. Horn, (Reinhold Plastics Applications Series), Reinhold Publishing Corporation, New York, 1960 and Encyclopedia of Polynwr Science and Technology, Vol. 1, pages 246-328, John Wiley & Sons, lnc., New York 1964 and which publications are in toto incorporated herein by reference.

The need for flame retarding polyacrylates has also been recognized in the art as exemplified by the two above-described publications and by US. Pat. No. 3,422,048 which is incorporated herein by reference.

The resultant disadvantages in the utilization of various prior art materials as flame retardants for polyacrylates include, without limitation, factors such as thermal migration, heat instability, light instability, non-biodegradable, toxicity, discoloration and the large amounts employed in order to be effective. Thus, there is always a demand for a material which will function as a flame retardant in polyacrylates and concurrently will not, by incorporation therein, adversely effect the chemical and/or physical and/or mechanical properties of the resultant composition.

The prior art problem of providing a flame retarded polyacrylate composition having desired chemical, physical and mechanical properties has now been substantially solved by the present invention and the above-described disadvantages substantially overcome Accordingly, one of the main objects of the present invention is to provide polyacrylate compositions which are flame retarded.

Another object of the present invention is to provide a material for polyacrylate compositions which will not substantially adversely effect the chemical and/or phys-,

ical and/or mechanical properties of said compositions.

A further object of the present invention is to provide a flamc retardant which is economic and easy to incorporate into polyacrylate without being degraded or decomposed as a result of blending or processing operatrons.

It has been found that the foregoing objects can be obtained by the incorporation of a new class of bisaryloxy compounds in polyacrylate to subsequently provide flame retarded compositions which exhibit outstanding chemical, physical and mechanical properties.

The bis-aryloxy compounds used in the present invention compositions have the formula:

m @lo (alkylenc)--O (aryl) In Formula 1 above, aryl is from the group Z is bromine or chlorine; in and m are integers each independently having a value of l-7; i and i' are integers each independently having a value of 02; alkylene is a straight or branched chain alkylene group having from one to six carbon atoms e.g, CH C H,, C H C Hg, CgHltla C H g, and A is fronl the group cyano (CN), nitro (-NO lower alkoxy (e.g. OCH:;, OCH,,), lower alkyl e.g. CH C H5, C H C,H,,, fluorine, dialkylamino e.g. N(CH,,) -N(C H phenyl (-C,,-H halo-phenyl, benzyl (Cll C H and halo-benzyl; and y is an integer having a value of l-5.

In Formula 1, the sum ofi+ m or i m is not greater than 7 and i y is not greater than 5.

It is to be understood that all of the compounds falling within the above Formula 1 and as heretofore defined are generically described herein as bis-aryloxy" compounds.

Illustrative (but without limitation) of some of the present invention bis-aryloxy compounds are shown below:

Z Ill the exemplary definitions of A, Z, alkylene, aryl, m, m, i, i and y are listed in Table l.

In general, the bis-aryloxy compounds are prepared by reacting a halogenated naphthol with a halogenated alkane or a monohalophenoxy haloalkane (depending upon which bis-aryloxy compound is desired) at elevated temperatures in the presence of a basic material such as alkali metal hydroxides, carbonates, bicarbonates, oxides and hydrides. The preferred alkali metals are potassium and sodium. Where one desires to increase, for example, ease of handling the reaction mass, solvents such as ketones (e.g. acetone, methyl ethyl ketone, and methyl iso-butyl ketone), alcohols (e.g. methanol, ethanol, iso-propyl alcohol, butyl alcohol and glycols), or aqueous solvents (e.g. water, a mixture of water and alcohol and a mixture of water and ketone) can be employed. The desired end product, i.e. the bis-aryloxy compound, can be recovered from the reaction mass via various methods such as distillation or crystallization after cooling the reaction mass to about l0-30 C and adding water thereto. Where the end product requires recovery via crystallization, various aromatic solvents such as benzene, toluene, xylene, dichlorobenzene and the like can be used.

Specifically, the bis-naphthoxy compounds are prepared according to the following reactions:

In the above reaction, X is halogen, preferably chlorine and alkylene is the same as defined herein. Where in and m and iand i are different integers, then equiv- In the above reaction, X is halogen, preferably chlorine, and alkylene is the same as defined herein.

The above reactions are conducted at temperatures ranging from the freezing point of the initial reaction mass to the boiling point thereof. Preferably the temperatures are from about 40 C to about 200 C and more preferably from about 50 C to about C. It is to be understood that the reaction can be conducted under sub-atmospheric (e.g. 1/10-8/10 atmospheres), atmospheric or super-atmospheric (e.g. l.5l0 atmospheres) pressure. Preferably, the reaction is carried out at atmospheric pressure.

The above-described processes can be carried out with conventional, readily available chemical processing equipment. For example, a conventional glass-lined vessel provided with heat transfer means, a reflux condenser and a mechanical stirrer can be advantageously utilized in practicing any of the preferred embodiments of the invention described in the examples set forth herein.

The amount of bis-aryloxy compound employed in the present invention compositions is any quantity which will effectively render the polyacrylate containing composition flame retardant. In general, the amount used is from about 1 to 25 percent by weight, based on the total weight of the composition. Preferably, the amount employed is from about 5 to about 20 percent by weight. It is to be understood that any amount can be used as long as it does not substantially adversely effect the chemical and/or physical and/or mechanical properties ofthe end polymer composition. The amount utilized, however, is such amount which achieves the objectives described herein.

It is to be understood that the terms polyacrylates as used herein means acrylic polymers including acrylic acid polymers and copolymers and acrylic ester polymers and copolymers. For example, there may be mentioned materials which contain one of the repeating units CH3 and CH2C- (Methacr'ylate polymers) CH- CH- O O R (Acrylate polymers) compositions is any polyacrylates herein defined and which one so desires to flame retard. It is to be understood that the polyacrylates used can be a virgin' material, i.e. substantially free of additives such as stabilizers, plasticizers, dyes, pigments, fillers, and the like, or the polyacrylates can have additives (such as those mentioned and described herein) already contained therein or added concurrently with or after the addition of the bis-aryloxy compounds.

Another facet of the present invention relates to the use of certain metal compounds with the bis-aryloxy compounds to promote a cooperative effect therebetween and thus enhance the flame retardency of the resultant plastic composition as compared to the flame retardancy of either one component used separately. These enhancing agents are from the group antimony, arsenic, bismuth, tin and zinc-containing compounds. Without limitation, examples of said enhancing agents include Sb O- SbCl SbBr SbI- SbOCl, AS203, AS205, 211804, BaB2O .H2O, 2.ZnO.3B 203.3.5-

\ H and stannous oxide hydrate. The preferred enhancing agent is antimony trioxide.

The amount of enhancing agent employed in the present invention compositions is any amount which when used with said bis-aryloxy compounds will promote a cooperative effect therebetween. In general, the amount employed is from about 1 to about percent, preferably from about 2 to about 10 percent, by weight, based on the total weight of plastic composition. Higher amounts can be used as long as the desired end result is achieved.

It is also within the scope of the present invention to employ other materials in the present invention compositions where one so desires to achieve a particular end result. Such materials include, without limitation, adhesion promotors; antioxidants; antistatic agents; antimicrobials; colorants; flame retardants such as those listed on pages 456-458, Modern Plastics Encyclopedia, ibid, (in addition to the new class of flame retardants described herein); heat stabilizers; light stabilizers; pigments; plasticizers; preservatives; ultraviolet stabilizers and fillers.

In this latter category, i.e. fillers, there can be mentioned without limitation, materials such as glass; carbon; cellulosic fillers (wood flour, cork and shell flour); calcium carbonate (chalk, limestone, and precipitated calcium carbonate); metal flakes; metallic oxides (aluminum, beryllium oxide and magnesia); metallic powders (aluminum, bronze, lead, stainless steel and zinc); polymers (comminuted polymers and elastomerplastic blends); silica products (diatomaceous earth, novaculite, quartz, sand, tripoli, fumed colloidal silica, silica aerogel, wet process silica); silicates (asbestos, kaolimite, mica, nepheline syenite, talc, wollastonite, aluminum silicate and calcium silicate); and inorganic compounds such as barium ferrite, barium sulfate, molybdenum disulfide and silicon carbide.

The above mentioned materials, including fillers, are more fully described in Modern Plastics Encyclopedia, ibid, and which publication is incorporated herein (in toto) by reference.

The amount of the above described material employed in the present invention compositions can be any quantity which will not substantially adversely effect the desired results derived from the present invention compositions. Thus, the amount used can be zero (0) percent, based on the total weight of the composition, up to that percent at which the composition can still be classified as a plastic. In general, such amount will be from about 0 to about 75 percent and specifically from about 1 to about 50 percent.

The bis-aryloxy compounds can be incorporated in to the polyacrylates at any processing stage in order to prepare the present invention compositions. In general, this is undertaken prior to fabrication either by physical blending or during the process of forming polyacrylates per se. Where one so desires, the bis-aryloxy compounds may be micronized into finely divided particles prior to incorporation into the polyacrylates.

EXAMPLE I A virgin polymethylmethacrylate plastic material, (Lucite-l 80, a product of E. l. duPont de Nemours and Company, Wilmington, Delaware and being substantially free of additives) is utilized as the base resin in order to prepare 26 formulations (plastic compositions). With the exception of formulation No. l, the particular bis-aryloxy (and the antimony trioxide enhancing agent where indicated) is incorporated into the plastic by adding both to a Brabender mixer ("Plastic- Corder," Torque Rheometer, Model PLV-l50, C. W. Brabender Instruments Inc., South Hackensack, N.J.). The mixer is equipped with a pair of roller type blades positioned within a head provided with heat transfer means.

The resultant mixture is heated to about 300 C.; at this temperature, it is in a molten state. The percent ages by weight of each component utilized in the respective formulations are listed in Table II. Each formulation is discharged from the mixer and upon cooling solidifies and is ground into chips. The chips are subjected to compression molding in a Wabash press by placing said chips between two platens, the bottom of which contains four equal size depressions 3 inches by 5 inches by /8 inch deep. The top platen is then placed over the bottom platen and heat transfer means supplied thereto in order to melt said chips and thus provide solid samples (after cooling) for testing.

Portions of the samples of each respective formulation (Nos. 1-26) prepared according to the above described procedure are then subjected to two different standard flammability tests, i.e. UL 94 and ASTM D- 2863-70. The UL 94 is, in general, the application of a burner to a test specimen (strip) for a certain period of time and observation of combustion, burning, and extinguishment. This procedure is fully set forth in Underwriters Laboratories bulletin entitled UL 94, Standard for Safety, First Edition, September 1972 and.

which is incorporated herein by reference. ASTM No. D-2863- is a flammability test which correlates the flammability ofa plastic specimen to the available oxygen in its immediate environment; this correlation is stated as an Oxygen Index, 0.1., level predicated upon the percent oxygen in the gaseous medium which is required to just provide a steady state of continuous burning of the plastic specimen. This ASTM method is fully described in 1971 Annual Book of ASTM Standards Part 27, published by the American Society For Testing and Materials, 1916 Race Street, Philadelphia, Pa.; this publication is to be considered as incorporated (in toto) herein by reference.

The results of these flammability tests are shown in Table II.

TABLE II FLAMMABILITY DATA FOR POLYACRYLATE PLASTIC COMPOSITIONS CONTAINING BlS-ARYLOXY COMPOUNDS FORMULA- BlS-ARYLOXY COM- ENHANCING OXYGEN INDEX UL 94 TION POUND AGENT No. No. a sb,o 7,

1. 0 o 20.0 sa

4. 5 2o 0 225 sa 5. 5 20 10 30.0 SE-O TABLE I1 (ontinued FLAMMABILITY DATA FOR POLYACRYLATE PLASTIC COMPOSITIONS CONTAINING BIS-ARYLOXY COMPOUNDS FORMULA- BlS-ARYLOXY COM ENHANCING OXYGEN INDEX UL 94 TION POUND AGENT NO. NO. Sb O 7? 6. 15 20 22.0 SB 7. I 20 29.5 SE0 8. 27 2O 0 235 SB 9. 27 l0 31.5 SE-O I0. 33 20 0 22.5 SB 11. 33 20 10 29.5 SE-0 l2. 20 0 22.0 SB 13. 4O 20 10 29.0 SE-O i4. 53 20 0 22.0 SB l5. 53 20 10 30.5 SE 0 I6. 58 20 0 21.0 SB 17. 58 20 10 29.0 SE-O 18. 65 20 0 21.5 SB 19. 65 20 [0 28.5 SE-l 20. 73 20 0 23.0 SB 2l. 73 20 10 30.0 SE-O 22. 77 20 0 23.5 SB 23. 77 20 10 31.0 550 24. 83 20 0 225 SB 25. 83 20 10 30.0 SE-O 26. 91 20 10 31.0 SE-O Referring to Table II, the bis-aryloxy number number relates to the structural formulae heretofor set forth in Table I; a difference of 2 percent in the Oxygen Index values is considered significant; and the UL 94 values are on a graduated scale wherein the highest degree to lowest degree of flame retardancy is respectively SE-O, SE-l, SE-Z, SB and Burns.

The results shown in Table II demonstrate the unique effectiveness of these bis-aryloxy compound as flame retardants for polyacrylates. Specifically, formulation No. l (the control) had a 0.1. of 20.0 and UL 94 value of SB. 1n the even numbered formulations, the use of the particular bis-aryloxy compound results in a significant increase in tire retardancy as measured by 0.1. (While these formulations also has a SB rating, UL 94, the individual U.L. rating has a wide range of values and thus the 0.1. number is, in this case, more indicative of increased flame retardancy).

The use of an enhancing agent such as Sb 0 to promote a cooperative effect between such agent and the bis-aryloxy compound is fully demonstrated via the results obtained from testing the odd numbered formulations. The highest UL 94 ratings and significantly higher 0.1. values are obtained when using an enhanc' ing agent.

EXAMPLE 11 Example 1 is repeated twice; once using a 10 percent bis-aryloxy compound level and 3 percent Sb 0 level and secondly. l5 and 5 percent levels respectively. At both levels, the 0.1. values and UL 94 ratings are slightly lower than the 20 percent level of Example 1.

EXAMPLE llI Portions of the solid samples of Formulation Nos. l-26 prepared according to the above described procedure of Example 1 are subjected to the following ASTM tests in order to ascertain other properties of the resultant plastic composition:

ASTM Test No. D638-61T; ASTM Test No. D790-63; ASTM Test No. D790-63; ASTM Test No. B25656; and

ASTM Test No. B64856.

Each of the aforementioned ASTM Tests are standard tests in the art and are utilized collectively in order to ascertain the efficacy of a polymeric system as an overall flame retarded composition for commercial application. All of these ASTM Tests are to be considered as incorporated herein by reference.

The results of these ASTM tests show that the physical properties of the present invention compositions are basically the same (except 0.1. and UL 94 values) as the plastic material without the flame retardant (i.e. formulation No. 1). Thus, there is no substantial adverse effect on the physical properties of the plastic material when the novel compounds are incorporated therein.

EXAMPLE IV The procedure of Examples 1, 11 and III are repeated except that the enhancing agent used is zinc borate instead of Sb 0 Substantially the same results are obtained using zinc borate as those obtained using Sb O EXAMPLE V Strip samples of each of Formulation Nos. 1 through 26 Table 11, are subjected to light stability tests via the use of a Weather-Ometer," modell 25/18 W. R.. Atlas Electrical Devices Company, Chicago, Illinois. Utilizing an operating temperature of F and a 50 percent relative humidity, each strip :is subjected to 200 hours of simulated daylight via the use of a carbon arc. The results show that after 200 hours, there is no significant discoloration in any strip tested and which demonstrates that the present invention compositions are highly resistant to deterioration by light.

EXAMPLE V1 Samples of each of Formulation Nos. 1 through 26 Table ll, are subjected to temperature (thermal) stability tests via the use of thermal gravimetric analysis (TGA). This test employed the use ofa Thermal Balance," model TGS-l, Perkin-Elmer Corporation, Norwalk, Connecticut and an electrical balance, Cahn 2580 model, Cahn instrument Company, Paramount, California. The results of these tests show that the his aryloxy compound containing Formulations had more than adequate stability for melt processing and subsequent heat aging (i.e. high temperature applications) and thus demonstrating that the particular bis-aryloxy are quite compatible with the plastic material. The bisaryloxy compound stability thus aids in providing sufficient flame retardancy at the plastic decomposition temperature. This test also demonstrates that these compounds do not exhibit migration.

In view of the foregoing Examples and remarks, it is seen that the plastic compositions, which incorporate these compounds, possess characteristics which have been unobtainable in the prior art. Thus, the use of these compounds in the above described plastic material as flame retardants therefor is quite unique since it is not possible to predict the effectiveness and functionality of any particular material in any polymer system until it is actively undergone incorporation therein and the resultant plastic composition tested according to various ASTM Standards. Furthermore, it is necessary, in order to have commercial utility, that the resultant flame retarded plastic composition possess characteristics such as being non-toxic. Use of these compounds in the plastic material has accomplished all of these objectives.

The above examples have been described in the foregoing specification for the purpose of illustration and not limitation. Many other modifications and ramifications will naturally suggest themselves to those skilled in the art based on this disclosure. These are intended to be comprehended as within the scope of this invention.

What is claimed is:

l. A plastic composition containing polyacrylate having incorporated therein a flame retardant which is a bis-aryloxy compound having the formula:

G O-(alkylenQ-O-(nryl).

wherein aryl is from the group and is selected from the group consisting of bromine or chlorine; m and m are integers having a value of l-7; v is an integer having a value of l-S; 1' and i are integers having a value of 0-2; A is selected from the group consisting of cyano, nitro, lower alkoxy, lower alkyl, fluorine, dialkylamino, phenyl, halophenyl, benzyl or halobenzyl; and alkylene is a straight or branched chain alkylene group having from one to six carbon atoms.

2. The composition as set forth in claim 1 wherein alkylene is CH 3. The composition as set forth in claim 1 \vherein alkylene is C li 4. The composition as set forth in claim 1 wherein alkylene is C H,,-.

5. The composition as set forth in claim 2 wherein Z. is bromine.

6. The composition as set forth in claim 2 wherein Z is chlorine.

7. A plastic composition containing polyacrylate having incorporated therein a flame retardant which is a bis-aryloxy compound having the formula:

Z is selected from the group consisting of bromine or chlorine; in is an integer having a value of l-7; y is an integer having a value of 1-5; 1' and I" are integers having a value of O-2; A is selected from the group consisting of cyano. nitro, lower alkoxy, lower alkyl, fluorine. dialkylamino, phenyl, halo-phenyl, benzyl or halobenzyl; and alkylene is a straight or branched chain alkylene group having from one to six carbon atoms.

8. The composition as set forth in claim 7 wherein alkylene is C H,.

9. The composition as set forth in claim 7 wherein alkylene is C H 10. The composition as set forth in claim 7 wherein alkylene is C H 11. The composition as set forth in claim 8 wherein Z is bromine.

12. The composition as set forth in claim 8 wherein Z is chlorine.

13. A plastic composition containing polyacrylate having incorporated therein a flame retardant which is a bis-aryloxy compound having the formula:

Z is selected from the group consisting of bromine or chlorine; m and m are integers having a value of l-7; iand i are integers having a value of 0-2; A is selected from the group consisting of cyano, nitro, lower alkoxy, lower alkyl, fluorine, dialkylamino, phenyl, halophenyl, benzyl or halobenzyl; and alkylene is a straight or branched chain alkylene group having from one to six carbon atoms.

14. The composition as set forth in claim 13 wherein alkylene is C H 15. The composition as set forth in claim 13 wherein alkylene is C H 16. The composition as set forth in claim 13 wherein alkylene is C H 17. The composition as set forth in claim 14 wherein Z is bromine.

18. The composition as set forth in claim 14 wherein Z is chlorine.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 3 9 424 DATED i March 4, 1975 |NVENTOR( 1 Arnold L. Anderson It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 1, Column 11, line 67 (being the first line after the third structural formula) before the first word is insert ---Z--- Claim 13, Column 12, lines 45-50 (being the structural formula) delete the formula shown and substitute therefore the following:

0 O-(alkylene) -o Signed and sealed this 6th day of May 1975.

(SEAL) Attest 2 C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks 

1. A PLASTIC COMPOSITION CONTAINING POLYACRYLATE HAVING INCORPORATED THEREIN A FLAME RETARDANT WHICH IS A BIS-ARYLOXY COMPOUND HAVING THE FORMULA:
 2. The composition as set forth in claim 1 wherein alkylene is C2H4.
 3. The composition as set forth in claim 1 wherein alkylene is C3H6.
 4. The composition as set forth in claim 1 wherein alkylene is C4H8.
 5. The composition as set forth in claim 2 wherein Z is bromine.
 6. The composition as set forth in claim 2 wherein Z is chlorine.
 7. A plastic composition containing polyacrylate having incorporated therein a flame retardant which is a bis-aryloxy compound having the formula:
 8. The composition as set forth in claim 7 wherein alkylene is C2H4.
 9. The composition as set forth in claim 7 wherein alkylene is C3H6.
 10. The composition as set forth in claim 7 wherein alkylene is C4H8.
 11. The composition as set forth in claim 8 wherein Z is bromine.
 12. The composition as set forth in claim 8 wherein Z is chlorine.
 13. A plastic composition containing polyacrylate having incorporated therein a flame retardant which is a bis-aryloxy compound having the formula:
 14. The composition as set forth in claim 13 wherein alkylene is C2H4.
 15. The composition as set forth in claim 13 wherein alkylene is C3H6.
 16. The composition as set forth in claim 13 wherein alkylene is C4H8.
 17. The composition as set forth in claim 14 wherein Z is bromine.
 18. The composition as set forth in claim 14 wherein Z is chlorine. 